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Boiler Sizing

Wayco Wayne_2
Wayco Wayne_2 Member Posts: 2,472
Heat loss is heat loss. I don't add for the indirect usually, unless there are unusual circumstances. What kind of boiler are you putting in? WW

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  • Boston
    Boston Member Posts: 71
    Boiler Sizing with floor warming

    We are building a new 4300 sq ft house - heat loss has been done for 2 hydo air zones. We added about 1000 sq ft of floor warming on all tile surfaces - all rooms that have radiant will have forced air from the hydo air system.

    question is, do we need to put in the next size up boiler - i say no, heat loss is heat loss no matter how it is delivered.

    There will also be a indirect tank off the boiler, load was added in.
    I thik the boiler is already one size too big based on the "safety factor".

    Any opinons would be welcome. We are ordering the boiler in the morning!

    Floor warming was viega climate panel. Good stuff.
  • Brad White_114
    Brad White_114 Member Posts: 4
    I agree

    Stick to your guns, Brian. Wayne is right.

    An over-sized boiler would be over-sized on the coldest day (less than 1% of the winter), and more over-sized as it gets warmer out. Hard to compensate for that.

    And yes, what kind of boiler? Hoping a mod-con.
  • Boston
    Boston Member Posts: 71
    mod con vs. weil mclane gold

    I think I am going to go "low-tech" and put in my old standard - weil mclane. Why?

    - A power vent is a pain now in Massachusetts and we have a chimney all ready to go

    - We use isocyanene (sp) insulation so I think we have a pretty tight house

    - I want to do it once and not have to worry about it for a long while

    - I may wind up not moving in and selling the house - so people like to see a "standard" boiler and indirect. No explanation required about the small, wierd mod-con boiler.

    It is difficult enough to deal with the plumber - he was sizing the boiler based on the heating coils in the hydro air units, plus a little more for the radinat garage, plus a little more for the hot water . I asked him what would it mean if the HVAC guys oversized the coil? Or undersized it?

    He is bringing in someone from the supply house to do a heat loss.

    I can still change the boiler. Can anyone dollarize (roughly ) the cost benefit? Spend 2000 more save 500/yr?

    I am old fashioned, I admit it.
This discussion has been closed.